Kumari Anshu, Kumari Kalpana, Gupta Sharad
Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore Indore India-453552
Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore Indore India-453552.
RSC Adv. 2019 Jun 13;9(32):18703-18712. doi: 10.1039/c9ra03152a. eCollection 2019 Jun 10.
Multiphoton imaging, a highly effective diagnostic technique, has recently gained widespread attention for early-stage cancer detection. Tremendous efforts have been dedicated to explore various types of exogenous contrast agents for improved signal-to-noise ratio of multiphoton imaging. Indocyanine green (ICG), the only U. S. FDA approved near-infrared chromophore, has been recently used as an exogenous contrast agent for two-photon bioimaging. Despite its great potential applications in clinical settings, the conventional delivery method of ICG has limited applications due to its poor cellular uptake and optical stability in its free form. Herein, we report the effect of nanoencapsulation of ICG on two-photon bioimaging. For this study, ICG was encapsulated within poly-l-arginine (PLA) based nanoparticles for the first time. These nanoparticles were found to be biocompatible and biodegradable as the major constituents were salts and PLA. These nanoparticles were spherical with a mean diameter of ∼61 nm and exhibit higher photostability than free ICG. Additionally, nanoencapsulated ICG treated cells show enhanced contrast for two-photon bioimaging in comparison with its free form. In summary, nanoencapsulated ICG could serve as an exogenous chromophore for multiphoton imaging, which shows excellent delivery efficacy.
多光子成像作为一种高效的诊断技术，最近在早期癌症检测方面受到了广泛关注。人们付出了巨大努力来探索各种类型的外源性造影剂，以提高多光子成像的信噪比。吲哚菁绿（ICG）是唯一获得美国食品药品监督管理局（FDA）批准的近红外发色团，最近已被用作双光子生物成像的外源性造影剂。尽管其在临床应用中有巨大潜力，但ICG的传统给药方式由于其游离形式的细胞摄取差和光学稳定性有限，应用受到限制。在此，我们报告了ICG纳米封装对双光子生物成像的影响。在本研究中，ICG首次被封装在基于聚-L-精氨酸（PLA）的纳米颗粒中。由于主要成分是盐和PLA，这些纳米颗粒被发现具有生物相容性和可生物降解性。这些纳米颗粒呈球形，平均直径约为61nm，并且比游离ICG表现出更高的光稳定性。此外，与游离形式相比，纳米封装ICG处理的细胞在双光子生物成像中显示出增强的对比度。总之，纳米封装ICG可以作为多光子成像的外源性发色团，显示出优异的递送效果。
